Signal the driver to ready the specified channel
#include <sys/asoundlib.h> int snd_pcm_channel_prepare( snd_pcm_t *handle, int channel );
The snd_pcm_channel_prepare() function prepares hardware to operate in a specified transfer direction by calling snd_pcm_capture_prepare() or snd_pcm_playback_prepare(), depending on the value of channel.
This call is responsible for all parts of the hardware's startup sequence that require additional initialization time, allowing the final GO (either from writes into the buffers or snd_pcm_channel_go()) to execute more quickly.
This function may be called in all states except SND_PCM_STATUS_NOTREADY (returns -EBADFD) and SND_PCM_STATUS_RUNNING state (returns -EBUSY). If the operation is successful (zero is returned), the driver state is changed to SND_PCM_STATUS_PREPARED.
EOK on success, a negative errno upon failure. The errno values are available in the errno.h file.
QNX Neutrino
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | Yes |
Thread | Read the Caveats |
This function is not thread safe if handle (snd_pcm_t) is used across multiple threads.